Scott's with a blonde

Three very different conversations led to me a corner table in Scott's in Mayfair with a negroni in my hand, awaiting a blonde 30 years my junior.

The first had been with my wife, who was happy to have her place taken by our non-meat-eating daughter on this dinner date just before her birthday.

The second had been over a drink with an American friend now a hedge-fund manager based in Berkeley Square. He had already confessed that he eats out on business at least eight times a week over four lunches and four dinners, a number far in excess of any restaurant reviewer. When I probed him for the one restaurant he invariably chooses as the most reliable, his immediate response was 'Scott's'.

My final conversation was with Danny Meyer, the New York restaurateur. Meyer is now facing the prospect of having to close Union Square Café, the restaurant that established his reputation when he had the foresight to open in what was then a run down part of the city 30 years ago, at the end of 2015 as a result of his landlord's demands for a 300% rent increase and a lease renewal of only 10 years.

Meyer's case goes beyond the particular. Restaurateurs have over the past 20 years opened up parts of numerous cities around the world where formerly other retailers feared to tread. But it now seems they could be priced out of the very neighbourhoods they have made safe and popular.

As cities increasingly come to be defined by their restaurants, how much will their reputations suffer if and when these landmarks are forced to close? La Coupole did a great job for the reputation of Paris many years ago. What would the citizens of Copenhagen or Girona have had to spend to generate the excitement that the chefs at Noma or El Celler de Can Roca have delivered on their behalf?

London is fortunate in that it still possesses several restaurants that have become landmarks in their own right. Most venerable are Rules, opened in 1798; J Sheekey in 1895; Bentleys in 1916; and Scott's, which originally opened on the Haymarket in 1892 before transferring to its current location in 1968.

History is not, of course, enough to justify survival in a business where any restaurant's reputation is only as good as the last meal it served, and Scott's went through a dismal era for 20 years before its renovation under Richard Caring in 2007. Today, I am reliably informed, Scott's can take more than £35,000 on a busy day.

Union Square Café and Scott's have become landmarks of their respective cities and although different in many ways, their respective success has two essential factors in common.

The first, and less obvious, is just what a gamble opening any restaurant is and quite how strongly that essential hunch about a location has to be backed up. Back in 1985, the 27-year-old Meyer was gambling practically his entire savings. By 2007 Caring was not only a successful businessman but also the owner of The Ivy and Le Caprice restaurants. He could certainly afford the £3.5 million renovation Scott's required, but socially he had far more to lose. Scott's was showing its age and a Mount Street address was not then the haven it is today, neither for those intent on making money nor for those equally intent on spending it.

The other crucial factor is that the restaurateur must ensure that what is inside the front door of the restaurant matches what is outside the front door. In this regard, Meyer was a visionary in that Union Square's menu of friendly, approachable dishes based on the produce of the nearby Greenmarket struck an immediate chord with those who lived and worked nearby.

Caring started with an inbuilt advantage in that fish had been the leitmotif of Scott's menu for decades. Fish appeals equally to men and women; it commands a reasonably high sales price; and, unlike meat, it can be served swiftly to those, particularly at lunch, who are 'cash rich but time poor'.

Scott's menu is written very much with such customers in mind. (The restaurant's wifi password is printed on the right-hand side of the menu.) Two bearded chefs man the magnificent crustacean bar in the centre of the room, compiling many of the cold first courses, a system that allows the main kitchen to concentrate on the main courses.

Our first courses - six different varieties of oysters served with hot wild boar sausages and a ceviche of sea bass, served cool, laced with avocado and enlivened with jalapeno chilli, were excellent - but it was the grilled fish of the day that was stunningly good. This was a whole turbot for two, its skin appropriately salted, the flesh still firm and gelatinous, the very finest version of this dish I have eaten anywhere other than Elkano restaurant near San Sebastian, north-east Spain, which has the essential advantage of overlooking the sea. With this, we drank a 50cl carafe of bone-dry 2011 Alsace Pinot Blanc from Domaine Ostertag and, with dessert, racked up a bill of £230.

Londoners are fortunate that Scott's management is intent on preserving its landmark status. I hope New Yorkers will be equally fortunate with the future of 21 East 16th Street.